1. Field of the Invention
The present invention relates to chairs, and in particular, to a task chair for supporting a seated user thereon in an ergonomic manner.
2. Description of the Related Art
Task chairs are commonly used by persons while working in a seated position in an office or other occupational environment. Typically, such chairs include a caster wheel assembly for rolling movement over a floor surface, as well as a number of manual adjustment features to allow the user to adjust the shape or movement characteristics of the chair to a desired configuration.
Many task chairs include a rigid seat pan and a rigid backrest pan, the seat pan and backrest pan including a layer of foam padding thereon which is covered by a decorative upholstery material. Although the foam padding provides some cushioning support for a seated user, the rigid and noncompliant seat pan and backrest pan may become uncomfortable to the user, especially if the user is seated at the chair for an extended period of time. In this connection, if the layer of foam padding is too thin, the user""s ischium or tail bone may abut the rigid seat pan to cause discomfort, and, if the layer of foam padding is too thick, the seat may not provide a firm overall support for the user.
Other known task chairs include seats having a relatively rigid outer frame supporting a mesh or webbing material thereacross which is flexible to conform to the seated user. However, such mesh or web material may catch, wear, or snag a user""s clothing when the user shifts positions in the chair or stands up from the chair. Also, such mesh or webbing material is somewhat frictionless, such that when a user uses the forward tilt mechanism of the chair, the user experiences the sensation of falling forwardly or sliding out of the chair. Similarly, when the user moves to a reclined posture in such chairs, the user tends to slide forwardly out of the chair, and the lumbar region of the user""s back disengages from the lower portion of the backrest.
What is needed is a task chair which conformingly and comfortably supports a seated user, and which is an improvement over the foregoing.
The present invention provides a task chair including a seat support structure, and a seat supported by the seat support structure having a seating surface which may ergonomically conform to a seated user. The seating surface includes rigid and flexible portions connected to one another, the flexible portions allowing resilient flexing of the seating surface to create conformance zones which dynamically support a seated user in an ergonomic manner.
The rigid portions of the seat may be formed of wood, metal, or a rigid plastic, for example, and the flexible portions may be formed of a pliable urethane or a silicone material, for example. The rigid and flexible portions may be connected to one another by insert molding the flexible portions to the rigid portions, or by mechanically or adhesively joining the flexible portions to the rigid portions. The particular shape, size, and relative configurations of the rigid portions and the flexible portions may be selectively varied to provide seating surfaces having desired conformance and support characteristics for the seated user.
The seat support structure may include a seat flex lockout mechanism movable between a first position and a second position, wherein flexing of the seating surface is prevented in the first position and is allowed in the second position. Additionally, the seat support structure may include a mechanism which allows the seat to be moved between high, middle, and low positions.
Advantageously, the present task chair includes a seating surface having rigid portions which provide a relatively firm support to a seated user, and flexible portions which facilitate movement of the flexible and rigid portions of the seating surface, and which provide support to the seated user in selected zones of the seating surface. Additionally, the flexible portions permit the seating surface to resiliently flex from a relatively planar shape to a saddle or saddle-like shape which conforms to the seated user. Further, the saddle-like shape supports the seated user, preventing the user from experiencing the sensation of falling or sliding out of the chair.
In one form thereof, the present invention provides a chair, including seat support structure; and a seat supported by the seat support structure, the seat including a flexible portion and at least one rigid portion, the seat resiliently movable between a first position in which the seat has a substantially flattened shape, and a second position in which opposite sides of a front portion of the seat are flexed downwardly about a central portion of the seat to form a saddle-like shape.
In another form thereof, the present invention provides a chair, including seat support structure; and a seat supported by the seat support structure, the seat formed of a flexible material having at least one rigid member embedded therein, the seat resiliently movable between an unflexed position and a flexed position in which opposite sides of a front portion of the seat are flexed downwardly about a central portion of the seat to provide a saddle-like shape.
In a further form thereof, the present invention provides a chair, including seat support structure including a rigid support member; and a seat supported by the seat support structure, the seat including a flexible portion disposed centrally within the seat, the flexible portion supported by the rigid support member; a rigid portion disposed along each side portion of the seat opposite the flexible portion, the seat resiliently movable between an unflexed position and a flexed position in which the side portions of the seat flex downwardly about opposite sides of the flexible portion to form a saddle-like shape.